1. Field of the Invention
The present invention relates to a method of molding, while vibrating, a mixture of materials for a friction member (a brake lining, a disc pad and a clutch facing) for vehicles and industrial machines, which are press-molded under high pressure, while using rubber, resin or the like as a binder. More particularly, the present invention relates to a molding method capable of controlling the physical properties and performance of a friction member in accordance with vibrating conditions.
2. Related Art Statement
In general, friction members, which employ rubber, resin or the like as the binder thereof, are molded in such a manner that a previously-molded member manufactured by molding a mixture of materials at room temperature or the mixture of materials is injected into a mold, which has been heated by an electric heater, so that it is molded by a hydraulic press under pressure.
The major factor of the physical properties and the performance of a frictional material are determined at the time of the press molding. However, the above-described conventional molding method has been performed in accordance with only the following four molding conditions: temperature, pressure, time and the venting condition.
The above-described four molding conditions are respectively usually set in safety regions in terms of maintaining the physical properties and the performance. Therefore, it is difficult to precisely adjust the physical properties and the performance by changing the above-described molding conditions. Accordingly, it might be considered feasible to employ a method which is arranged in such a manner that the physical properties and the performance are adjusted by adjusting the weight of the previously-molded member or by changing the molding pressure. However, a problem arises in that the obtained physical properties and the performance show wide deviation.